This invention relates to an installation structure of a parallel wire on a board, wherein wire parts of strip-off margins at both ends of a parallel wire are bent before insertion into a board and the wire parts are prevented from slipping out at the bent portions for soldering in a dip bath when the wire parts are inserted into the board.
In an installation structure of a parallel wire on a board in a related art, wire parts 102 of strip-off margins at both ends of a parallel wire 101 are formed with bent portions 102a and 102b each of which are U-shaped, and bent in the same left-right direction, as shown in FIG. 3(a). If the respective wire parts 102 at both ends of the parallel wire 101 are inserted into a board 103, the bent portions 102a and 102b of the wire parts 102 are placed in the left-right opposite directions, as shown in FIG. 3(b). If solder 104 is put on the bent portions 102a and 102b (wire parts 102) by soldering in a dip bath, as shown in FIG. 3(c), the right bent portion 102b is not uniformly soldered and a solder break occurs, causing tunnel solder to occur, and the solder 104 does not uniformly accumulate on the bent portions 102a and 102b on both sides; this is a problem.
A first related art is shown in FIGS. 4(a), 4(b), and 4(c). The mounting structure of electronic parts in the first related art is a mounting structure of a mechanical switch 209 with terminals 209e and 209f soldered to a printed wiring board 210 by allowing the unit to flow into a soldering bath in a state in which the terminals 209e and 209f projected from the mechanical switch 209 are inserted into terminal attachment holes 210a formed on the printed wiring board 210, wherein the lower end parts of the terminals 209e and 209f projected from the terminal attachment holes 210a are bent ±90 degrees or less in the moving direction of the printed wiring board 210 with respect to the soldering bath. (For example, refer to Japanese Patent Publication No. 2001-94242.)
In the first related art, however, the terminals 209e and 209f of the electronic component are soldered and fixed to the printed wiring board 210 and a parallel wire is not installed in a board.
A second related art is shown in FIG. 5. In a parts mounting method on a board in the second related art, copper foil, a resist, an adhesive, or a combination thereof 308 is provided on a board 304 and a component 301 is floated from the board 304, as shown in FIG. 5. A bank 303 of air heated in a soldering bath 307 and expanded is released through the gap between the component 301 and the board 304. (For example, refer to Japanese Journal of Technical Disclosure No. 2001-2170.)
In the second related art, however, bent portions of left and right leads 302 of the component are bent in opposite directions to each other as in the installation structure of a parallel wire on a board in the related art described above and therefore solder does not uniformly accumulate on the leads 302; this is a problem.